The term prostaglandin refers to any member of the class of biochemicals synthesized by essential fatty acids that contain a chain of 20 carbon atoms, as well as a 5-carbon ring. The primary prostaglandin pathways are double-unsaturated omega-6 linoleic acid and triple-unsaturated omega-3 alpha-linolenic acid. The former occurs with the introduction of dihomo-y-linolenic acid (DGLA), which is obtained from organ meats. The other is initiated by arachidonic acid, which is found exclusively in animal fats and seaweed. It is the structure of arachidonic acid that contributes to forming the 5-member ring.
A complete prostaglandin definition should include the fact that these agents are actually hormones, although they are not officially classified as such. In fact, prostaglandins form various subsets of several larger families of fatty acid by-products, including leukotrienes, thromboxanes, lipoxins, and prostacyclins. Paired with thromboxanes and prostacyclins, prostaglandins make up a class of tissue specific hormones known as eicosanoids. However, even though these agents behave as chemical messengers and are thought to be the primary regulating components of virtually every cell, they do not circulate through the bloodstream like hormones do. Instead, they remain in residence in the cell where they were produced.
Prostaglandin function is not completely understood, but it is known is that they are key to an astonishing number of metabolic processes. For instance, they are involved in the transport of calcium, regulate inflammatory response, and are essential to cellular division and replication. Prostaglandins also influence platelets, meaning that they help to regulate clotting. They also stimulate the dilation and contraction of smooth muscle cells. In addition, prostaglandins play a role in fertility.
The reason for so much varied and complex activity is due to the fact that nine prostaglandin receptors that have been identified, each of which occupy different types of cells. This suggests that the potential for prostaglandin treatment in the future is quite promising and its impact easily recognized. The ability to selectively stimulate or inhibit prostaglandin activity could possibly be used to prevent and/or treat a great range of diseases. In fact, researchers have found that specific prostaglandins appear to offer protection from vascular disease and stroke. This type of therapy may also benefit those suffering from inflammatory disorders, such as asthma, lupus, and arthritis.
Prostaglandins are not specific to the human body by any means. In fact, they are active in nearly every form of living tissue. This extends to animals, insects, shellfish, and even coral.